The Role of Mitochondrial Homeostasis and Molecular Regulation of Mitochondrial Biogenesis in the Heart: Current data suggest that mitochondria may play a central role in the promotion of cell survival and adaptations to pathological stress across multiple cell/tissue types. In this project we are evaluating how proteins that control mitochondrial homeostasis are both regulated and how they modulate cardiac pathology including pressure overload and cardiac ischemia. The candidate proteins being explored include the biogenesis regulator PGC-1 alpha and proteins that modulate post-translational modifications in the heart including sirtuin proteins and Pink1. Human atrial appendage tissue is obtained to validate whether the findings identified in the laboratory are operational in patients undergoing coronary artery bypass surgery.